It would be (would have been) helpful if Adobe included all of the changes, and reasons for those, in their release document. They listed the new profiles, moving dehaze, and such but ignored other ones. I m sure that I am not the only user that went: "hey, where is the B&W tab?". I can guess (I am not a programmer) the reason for that, but it would have ben nice to be informed about it. My guess is that the conversion is now done in one of the b&w profiles, and that the generic one that was the default in the old tab was made into the new monochrome profile.